The invention relates to a seed drill with disk-type furrow openers which are rotatably supported on mounts displaceable in the vertical plane and whose individual furrow-opener disks are set at an acute angle relative to the direction of travel, there being disposed on said mounts skids which extend close to the outside of the individual opener disks, angled relative to the direction of travel, and whose sliding surface is located above the intended depth of soil penetration of the opener disks, in accordance with German patent application No. P 28 14 883.6, which corresponds with U.S. application Ser. No. 027,321, filed Apr. 5, 1974.
The seed drill there described has been found to be well suited for use particularly in direct seeding, that is to say, for placing seed in soil previously prepared for planting by means of cultivating implements, since in that application it is important that the root-infested soil raised by the furrow-opener disks not be turned over but be moved back unturned into the seeded furrow behind the opener disks, and that the tough stalks from the previous crop which the opener disks force into the soil rise again from the bottom of the furrow before the seeds are deposited so that the seeds are able to drop through them to the bottom of the furrow before the latter is closed.
Only when considerable plant growth has sprung up in the fields to be planted, or when there is an abundance of plant residues from the previous crop on the ground, will clogging between the furrow-opener disks and the skids occur. Such clogging will then necessarily disrupt planting.
However, when used in fields which have been conventionally prepared for planting by means of various cultivating implements, this seed drill has the drawback that the loose soil, particularly when it is moist and sticky, will adhere to the sliding surfaces of the skids, with the result that the latter will start to burrow in the soil and must be rid at frequent intervals of the adhering soil, which is time-consuming. A further disadvantage in this application and under these conditions is that such soil will also stick to the treads of the press wheels, thereby increasing the diameter of the latter and lifting the furrow-opener disks out of the ground. The adhering soil must then also be scraped off the press wheels at frequent intervals, which, too, is a tedious chore.